JP2714409B2 - Portable automatic tools - Google Patents

Abstract

A gasoline engine driven flexible line trimmer is provided with a modularly constructed power head section which significantly facilitates the original manufacturing assembly, and subsequent service disassembly, of the power head. In a clutch drive embodiment thereof, the power head has four readily separable modules - an engine module comprising a main engine shroud to which the engine is internally secured; a fan housing module; a starter module comprising a starter housing and a recoil starter mechanism retained therein; and a coupling module comprising a clutch housing carrying therein structure for operatively interconnecting the engine's clutch to the flexible drive shaft disposed within the trimmer shaft. In a direct drive version thereof, the power head has two separable modules - the engine module and a combined fan housing, starter and coupling module defined by a single housing within which the starter and coupling structure is carried. The main shroud is provided with a specially designed wall section which supports the engine, defines a closure wall of its crankcase, forms an air-fuel mixture passage for a carburetor externally supported on the wall section and supports a reed valve within the crankcase. The shroud defines an external protective recess in which the carburetor is positioned and, in one embodiment, defines a portion of the engine's fuel tank. Pull rope installation in the starter mechanism is facilitated and made safer by pulley locking and retaining structure incorporated in the starter module, and improved air filter element sealing is provided by virtue of a specially designed air filter housing and choke plate assembly associated with the carburetor. Shaft vibration transmitted to the trimmer user through the supporting shoulder strap structure is significantly reduced by a specially designed resilient strap connector assembly securable to the trimmer shaft.

Description

Description: TECHNICAL FIELD The present invention relates to an automatic tool, and more particularly to an improved head mechanism and a vibration reducing device for a portable automatic tool such as a flexible line trimmer.

(Prior Art) A portable engine-driven rotary automatic tool such as a brush cutter, a lawnmower, a flexible line trimmer, or the like has a longitudinal hollow shaft having a rotary cutting device operably mounted at one end. An electric head device having a driving engine is mounted on the other end of the hollow shaft and protects all or a part of the recoil starter mechanism including the engine, the fuel tank and the usual starter rope and pull handle member. Has a shroud. The cutting device is driven either directly by the engine by a flexible drive shaft passing through the hollow shaft or via a clutch mechanism. In order to assist in guiding the cutter element during use of the tool, a pair of operator handle elements are often fixed to the tool at a predetermined position, and a shoulder strap for receiving the tool weight is often added. Is detachably attached to a small rigid clamp member or the like fixed to a shaft.

While gasoline engine driven tools of this type and shape are extremely useful and popular,
There are also many problems, limitations and drawbacks regarding structure, operation, safety, manufacturing cost efficiency, operating comfort, maintenance and serviceability.

For example, since it is necessary to design a drive head mechanism that is light in weight, small in size, and cost-effective in consideration of materials and assemblability, the finally obtained drive head mechanism can be used by ordinary workers. It was awkward and cumbersome. Minor adjustments, such as adjusting the idle amount of the carburetor and resetting the speed adjustment screw, also required disassembling and removing many other drive head parts to expose the carburetor. Another maintenance problem is that many conventional drive heads of this type require complicated assembly, so that failure or removal of the main engine is impossible for ordinary workers.

Many conventional proposals for improving these handling properties can improve handling properties to some extent, but on the other hand, the exposure of parts causes the tool to collide with other objects or break during use. The danger increases and the appearance of the drive head becomes abnormal. An example of this is where the engine's carburetor and associated air filter structure protrudes out of the engine shroud to improve handling, making these components prone to breakage.

Another example of both handleability and safety of parts is the problem of recoil starter mechanisms, which are usually difficult to remove and difficult and dangerous to replace when changing starter ropes, as is well known. The starter pulley must be manually lifted against the urging force of the torsion spring, and a new starter rope must be tied to the pulley with one hand, while holding the pulled up pulley with the other hand to prevent the torsion spring from being opened. There was.

Apart from the many problems associated with the power head of such tools, a great deal of axial variation is transmitted to the operator via a shoulder strap fixed to the tool despite the flexibility of the strap. I knew it was there. The worker feels discomfort and fatigue due to the transmitted vibration. Therefore, it is highly desirable to solve this problem simply and at low cost.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an automatic tool which solves the above-mentioned problems of the prior art.

(Means for Solving the Problems) An automatic tool for achieving the above object of the present invention is provided with a working device that can be driven to perform a predetermined working function, and a rotational force received from a power source thereof. And a power transmission device that drives the working device by transmitting the power to the working device, and an automatic tool driven by an internal combustion engine including a power head mechanism, wherein the power head mechanism has a shroud member, and the shroud member is An opening front end; an engine support wall formed rearward from the opening front end; a fuel / air mixture passage extending through the support wall from an outer surface to an inner surface of the shroud member; A reed valve secured to the inner surface of the support wall over the air passage; and a chamber extending rearward of the support wall, the chamber communicating with an interior of the shroud member and a rear end. Has a release section The power head mechanism further includes an internal combustion engine that generates a rotational force, the internal combustion engine includes a crankcase partially surrounded by a shroud member, and an open rear end of the crankcase is configured to have the crankcase. A rear enclosing wall of the crankcase is formed by the support wall portion over a reed valve, and the internal combustion engine is supported by the engine support wall portion via a crankcase. Further, the internal combustion engine includes a cylinder connected to a side of the crankcase in the shroud member, a muffler fixed to the cylinder and located inside the chamber, and fixed to the outside of the support wall; A carburetor operatively located above the fuel / air mixture passage, the powerhead mechanism further comprising the shroud at the open front end. A housing member detachably connectable to the housing member; a coupling device located in the housing member, for rotatably connecting the internal combustion engine to the power transmission device; and a supporter inside a part of the housing member. Has been
A manual starter device for starting the internal combustion engine and detaching the starter device from the shroud member.

According to an embodiment of the present invention, a rotary automatic tool driven by an internal combustion engine in a flexible line trimmer includes a power head mechanism module mounted on one end of a hollow trimmer shaft and a cutting head mounted on the other end of the shaft. Used to drive the mechanism.

In one embodiment, the apparatus is constituted by modules which are detachably held, such as an engine module, a fan housing module, a starter module, and a coupling module, and the whole of the apparatus is formed from the front end to the rear end. The engine module includes an opening front end, an upper wall, a lower wall, a pair of opposing side walls, a thick upper rear supporting wall extending downward from a central portion of an upper end, and a lower wall extending rearward from a bottom of the supporting portion. And, along with the side walls, a vertical intermediate wall defining a muffler chamber having an open rear end to which a suitable muffler guard is connected. The upper wall of the shroud extends downward to form the upper wall of the shroud, and the open lower end of the shell member is sealed and secured around the recess to define a fuel tank portion of the engine module.

The rear portion of the upper wall, together with the intermediate wall and the support wall, forms a rear end recess in the shroud. The carburettor and the associated air filter housing are located in this recess so that the members can be accessed from damage as well as for repair or the like.

A reed valve fixed to the outer surface of the support for the fuel / air mixture passage extending inward of the carburetor is operably mounted on the inner surface of the support wall to the inner end of the mixture passage.

The engine module comprises a small one cylinder, an air-cooled two-cycle gasoline engine with a crankcase having an open rear end, a piston and cylinder arrangement extending from the crankcase and fixed to the crankcase, and supported projecting rearward from the cylinder. It has a muffler. The muffler section of the crankcase, cylinder and engine is provided in the shroud and can be removed from its front end. The open rear end of the crankcase is bolted to the inside of the thick support portion with respect to the reed valve, and the engine is supported by the support wall to form a rear surrounding wall of the crankcase. The cylinder extends into the middle of the shroud wall, and the muffler projects rearward of the muffler chamber. The crankshaft of the engine protrudes forward from the open front end of the shroud, and has a centrifugal clutch mechanism held at the front end by a nut screwed to the outer end of the crankshaft.

The fan housing module has a fan housing portion that surrounds a coaxially formed engine flywheel that is locked to a crankshaft in front of a crankcase and that is secured to a shroud about an open front end. The flywheel has a cooling impeller blade, and the outside air is supplied by the impeller blade during operation of the engine to cool the cylinder and is discharged outside from the muffler chamber. The cooled outside air mixes with the exhaust gas discharged from the muffler to cool the exhaust gas. The exhaust gas cooling air mixture is exhausted backward through the hole in the muffler guard.

The starter module has a side wall extending rearward from the periphery of the front wall and an open rear end, and the starter housing is detachably connected to an open front end of the fan housing. The tubular support post projects rearward from the front wall of the starter housing, and the manual recoil starter mechanism supported inside the starter housing, which is in contact with a part of the engine crankshaft between the clutch mechanism and the flywheel, is attached to the support post. A starter pulley is rotatably supported and has front and rear flanges around which the starter rope is wound, the outer end of the starter rope being operatively connected to a starter pull handle through a grommet opening in the starter housing.

The hollow cylindrical drive hub projects rearwardly from the center of the rear flange and has drive teeth operatively engaged with a spring-biased starter dog mounted on the front of the flywheel.
An annular torsion spring circumscribing the support post is operatively connected to the starter pulley and held between a front end of the starter housing and a front flange of the pulley. The starter pulley is housed in a substantially annular guide channel formed by a guide member extending rearward from the starter housing wall. The pulley is held on the support posts by small holding tabs secured to the thickened portion of the starter housing by machine screws. Thus, when the starter module is removed from the power head mechanism member, both the starter pulley and the torsion spring are retained within the starter housing.

The mounting of the starter rope of the starter pulley is sufficiently safe and easy due to the pulley and spring retaining action of a tab member having a circumferentially alignable notch formed around one of the pulley guide members and the rear pulley flange. You. In order to attach the starter rope to the pulley, the pulley is wound against the biasing force of the torsion spring and is opened almost one full turn until the two notches are aligned. A small pin member or the like is inserted into the aligned notch and locks the pulley against rotation generated by winding up the spring. After the operator's hands are free and a rope is attached that allows safe and easy handling of the starter rope, the locking pin is removed, the spring opens and a new rope is automatically wound on the starter pulley.

A coupling module connectable to the front side of the starter module has a clutch housing, which surrounds the engine's centrifugal clutch and has an aft bearing inside the bearing structure having an annular bearing and an annular bearing spacer. And a support shaft projecting therefrom. The bearing structure supports the coupling member on the cylinder so as to be rotatable coaxially, and the cylindrical coupling member is provided at the front end in the support shaft portion at the end of the flexible drive shaft which drives the cutting head of the trimmer through the tubular trimmer shaft. Locked. The clutch drum is fixed to the rear end of the coupling member and circumscribes the centrifugal clutch. When the engine speed reaches a predetermined level, the friction portion of the clutch moves radially outward and frictionally engages with the inner surface of the clutch drum to rotate the flexible drive shaft.

The power head module greatly improves the accessibility and serviceability of the internal power head components in a very cost-saving manner. For example, by simply removing the coupling module, the centrifugal clutch member can be easily accessed and conveniently held on the power head by a retaining nut at the outer end of the crankshaft. The starter and fan housing module are held in the shroud by the exposed clutch mechanism. By removing the clutch device, the starter device can be pulled outward from the front end of the crankshaft. In addition, removal of the fan housing screws and fan housing exposes the flywheel and ignition module for service.
The entire engine is achieved by connecting the shroud support wall and by removing the engine from the open front end of the shroud. The accessible carburettor and its associated air filter structure located in the recess of the protective shroud are simply pulled out of the uniquely shaped support wall of the shroud.

In a direct drive embodiment of the power head device, the centrifugal clutch mechanism is omitted and one fan housing and starter module are releasably mounted at the open front end of the shroud. The integral front module has an integral housing with the recoil starter system retained and the coupling member supported to driveably connect the inner end of the flexible drive shaft to the outer end of the crankshaft.

In another variant of the power head device, the upper shroud recess and the rear of the upper shroud wall are omitted.
The separate fuel tank has a recess suitably secured to the upper front of the shroud and spaced upwardly from the shroud wall and extending rearward from the shroud wall to form a protective recess in which the carburettor and its associated filter structure are provided. In another embodiment of the powerhead device, the shroud is similarly modified and the operator handle is fixed at the top of the powerhead. The operator's handle has a front end connected to the housing in front of the shroud, and a rear part fixed to the front end of the shroud and configured by a fuel tank covering a carburetor or the like.

In accordance with a feature of the present invention, a uniquely configured carburetor yoke plate and air filter device are secured to a shroud support wall against the rear end of the carburetor, and the yoke that cranks the carburetor on a mixture passage passing through the support wall. It has a plate. The yoke plate is secured within the open front end of the air filter housing, has a yoke lever pivotally attached to its rear end, and has a moveable inner end over the central yoke opening of the yoke plate. And selectively controls the shielding of the opening. A projection is formed on the yoke lever and selectively retains the yoke lever in one of the three yoke positions in conjunction with a recess formed in the back of the yoke plate.

The air filter housing has a side wall with a series of air intakes to flex and support the foamable air filter material. The outer end of the yoke lever extends outward from the cutout of the filter housing, and when the yoke lever sealingly engaged with the front edge of the filter material rotates relative to the yoke plate, the side edge of the filter element becomes Deforms to form a dust seal around the outer end of the yoke lever in the new pivot position.

According to the present invention, a specially designed coupling device is used to connect the worker's shoulder strap to the trimmer shaft to greatly reduce shaft vibration transmitted to the worker via the strap. The coupling device comprises a first substantially rigid member fixed to the trimmer shaft, a second substantially rigid member to which the shoulder strap is fixed, a hollow elastic vibration reducing member, and the first and second members formed of a hollow reducing member. A connecting member connected to both ends to prevent the first and second members from coming into contact with each other, to apply vibration to the reducing member via the first member, and to reduce the vibration by the flexibility of the reducing member. I have.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings.

As shown in the perspective view of FIG. 1, a portable automatic tool in the form of a flexible line trimmer 10 is provided as a preferred embodiment. This embodiment addresses various structural, operational, maintenance and serviceability improvements and cost reduction issues. The trimmer 10 has a longitudinal hollow shaft 12 having a rotary drive cutting head mechanism 14 at its left end.
It has. The head mechanism 14 rotates at a high speed so as to rotate a flexible trimming line member 16 which is substantially perpendicular to the rotation axis and protrudes outwardly into a cutting plane for cutting various plants on its moving surface. In order to protect the workers from the line member 16 turning at high speed, the protective shield member 18 is also pivoted.
The shield member is fixed to the outer end of the shield 12 and is located substantially above the cut surface and rearward toward the worker. An operating power head mechanism 20 having a unique shape is attached to the right inner end of the shaft 12 so as to transmit a rotational force to the cutting head mechanism 14. A small, one-cylinder internal combustion engine 22 (FIG. 3) is provided in a multi-piece plastic shroud and housing structure. As shown in FIG. 2, this structure includes a main shroud 24 located at the rear end of the power head mechanism 20, a fan housing 26 removably attached to the front side of the shroud 24 by mounting screws 28, and a fan housing 26. It has a starter housing 30 located on the front side of 26 and a clutch housing 32 projecting forward from the starter housing 30 and fixed to the inner end of the shaft 12 as described later. A longitudinal mounting screw 34 extends through the rear portion of the clutch housing 32 to the front side of the fan housing 26 via the starter housing 30, and detachably mounts the housings 30, 32 to the fan housing 26.

A hollow cylindrical operator handgrip 36 of a suitable resilient material coaxially circumscribes the shaft 12 immediately adjacent the outer end of the clutch housing 32. At the front end of the hand grip 36, a plastic-molded throttle lever housing 38 is detachably attached to the shaft 12, and is attached to a pivotally attached slot arm 44 (FIG. 5) of a carburetor 46 attached to the outside of the engine. It has a pivoting throttle lever 40 operatively connected via a cable member 42. First
As best shown, the cable 42 extends through an axial passage (not shown) formed in the hand grip 36 and enters the fan housing 26 at a location 48. As best shown in FIG.
Exits the rear shroud 24 near the carburetor 46,
The end is connected to the throttle arm 44.

A front operator handle 50 used by the trimmer operator in conjunction with the rear hand grip 36 to precisely control the movement of the trimmer cutting plane includes a slot lever housing 38.
In front of the shaft 12. A uniquely configured vibration reducing shoulder trap connector structure 52 is sandwiched between the housing 38 and the control handle 50 on the shaft 12. The connector structure 52 is connectable to an operator shoulder strap 54, as described below, which strap 54 is used by the operator in a conventional manner to comfortably support the weight of the trimmer 10.

As shown in FIGS. 2-4, the shroud and housing portions 24, 26, 30, 32 are "stacked" from front to back along the rear end of the shaft 12, and the mounting screws Alternatively, it can be easily disassembled by removing the bolts 28 and 34. The main shroud 24 is substantially rectangular in side and the top of the fan housing 26 is combined with a starter housing 30 and a clutch housing 32 to form a full housing structure having a generally frustoconical nose portion, comprising a multi-part housing. The structure has a good streamline shape.

The main shroud 24 has an open front end 56 and has a vertical, substantially rectangular cross-section defined by a top wall 58, a bottom wall 60, and a pair of side walls 62,64. A thick upper rear wall 68 extends downwardly from the upper shroud wall 58 and is connected to a rearwardly extending horizontal intermediate wall 70 at a lower portion thereof.

The inside of the main shroud 24 is opened outward at an opening front end 56, and is also provided rearward through a lower rear end opening 72 defined by the lower side 70 of the side walls 62 and 64 and the rear of the bottom wall 60. Also open to the public. A lower rear cavity 74 is formed in the shroud 24 by these specific walls. Also, in the shroud 24, the rear upper recess 76 includes a wall 68, vertically separated walls 58, 70, and an inclined rear tab 78 of the side wall extending inward beyond the vertically separated 58, 70 from each other. Are formed. As described above, the rear upper recess 76 is accessible from the rear of the shroud 24 and from opposite sides of the side wall tab 78 for repair or the like, and the boundary of the inner end is a thick rear wall.
68.

As described above, the fan housing 26 fixed to the front end 56 of the main shroud 24 has an open front end 80 and an open rear end 82. The starter housing 30 has a front wall 86 and an open rear end 84 from the center of the hollow cylindrical support member 88 extending rearward. The clutch housing 32 tapered forward and laterally inward has an open rear end 90 and an open front end 92, and a hollow cylindrical support shaft 94 extends rearward from the open front end.

Referring primarily to FIGS. 3 and 4, engine 22 is a single cylinder, air-cooled, two-cycle engine, installed in the aforementioned multi-part shroud and housing structure, except for the exceptional parts described below. The main components of the engine 22 are a finned cylinder 100, FIGS.
In the figure, a piston 102 housed in a cylinder so as to reciprocate along a vertical axis, a crank shaft mechanism 104, a crank case 106, and a series of circumferentially spaced cooling impeller blades extending in the axial direction. A flywheel 108 having a 110, a clutch mechanism 112, an ignition module 114, a spark plug 116, a muffler 118, a carburetor 46, an air filter housing, and a yoke plate mechanism 120. The crankcase 106 has a hollow rear end 122 having an open rear end 124,
126 and a forwardly projecting hollow cylindrical bearing support 128
have.

As described later, the main shroud 24 has various unique mechanisms in the power head mechanism 20 in addition to surrounding and protecting the rear part of the engine 22. Thick wall of shroud
One of the important functions described above by 68 is to mount and support the engine 22 as described below. Crankcase 106
The open rear end 124 is provided with four mounting bolts 134 (2 in FIG. 4).
(Only the book is visible), and is fixed to the inner surface of the thick portion 68 via the gasket 130 around the boss portion 132 projecting inward. Bolt 134 is in the rear shroud recess 76
And extends forward from the thick wall 68 and is secured to the crankcase end 124.

The thick wall portion 68 serves to attach the carburetor 46 and the filter and yoke plate mechanism 120 to the outside, as described later, inside the concave portion 76. The carburetor 46 is provided with a rear projecting end 135 of the boss 132, as best shown in FIG.
Is in contact with In FIG. 3, the thick wall portion 68 forms the rear surrounding wall of the rear portion 122 of the crankcase 106, and the appropriately shaped boss opening 136 connects the outlet of the carburetor connected to the inside of the rear crankcase portion 122. A mixture passage is formed. The boss 132 is shaped so that the schematically illustrated crankcase reed valve 138 can be easily attached to the inner end of the passage 136. Before describing other functions and advantages of the main shroud 24, the connection and relative positions of the aforementioned engine components will be described in detail.

The upper end of the finned cylinder 100 is suitably bolted to the lower opening 126 of the crankcase 106 via a seal gasket 140, and the bottomed spark plug 116 is provided with a suitable opening formed in the lower shroud wall 60. Protrudes downward through 142. Spark plug 116 is a suitable wire 144
Is operatively connected to the ignition module 114 by the ignition module 114, which is provided in the lower portion of the fan housing 26 and has a longitudinal mounting screw 148.
Connection block 146 protruding forward of the cylinder 100
It is fixed to.

The cylinder 100 has a suitably shaped exhaust gas outlet on the right side for receiving the inlet end 152 of the muffler 118. Cylinder
Exhaust gas exhausted from 100 flows into the muffler body via a perforated thin cylinder muffler liner 154 via an outlet opening 150. The muffler body is comprised of two partially telescopic horizontal sections (118a and 118b), the horizontal section 118a having an outwardly deformed portion forming a side outlet 156 in the muffler body. Exhaust gas entering the muffler main body via the liner 154 is discharged rearward through these side outlets 156 and is formed on a hollow plastic forming muffler guard 160 fixed to the shroud 24 over a lower end rear opening 72. It flows backward through the rear wall hole 158.

The filter and tip yoke plate mechanism 120 includes a metal tip yoke plate 162 located behind the carburettor 46.
And an air filter housing 164 located behind the chi-yoke plate 162. The thick yoke plate 162 is made of a thick shroud wall by a pair of long mounting screws 166.
Fixed to 68. Mounting screw 166
62 is pulled to the rear end of the carburetor 46, and operatively clamps the yoke plate 162 together with the boss 134 projecting rearward. As a result, the air-fuel mixture formed by the carburetor 46 flows into the crankcase 106 through the boss opening 136 and the reed valve 138. The filter housing 164 is fixed to the yoke plate 162 by a pair of mounting screws 168 that are fixed to the yoke plate 162 through the filter housing 164. Fuel is supplied to the carburetor 46 through the flexible fuel pipe 170 as described later. The crankshaft mechanism 104 has a relatively large-diameter longitudinal inner coaxial portion 172 passing through the crankcase support portion 128. The crankshaft mechanism includes an inner crank bearing 174 supported by a shaft portion 172.
And a bearing mechanism having a bearing support portion 128 protruding forward in the direction of the fan housing 26 and an outer crank bearing 176 held in the outer end portion. The left end of the inner shaft portion 172 is tapered at number 178 to be continuous with the small-diameter outer longitudinal shaft portion 180. The shaft portion 180 extends through the center of the starter housing 30 to the clutch housing 32 and extends to the outer end portion 182. Has a thread groove.

The flywheel 108 is located in the fan housing 26, and coaxially circumscribes a longitudinal center portion of the crankshaft including the tapered portion 178. Flywheel 108 is keyed or locked to the crankshaft to rotate with the crankshaft. Impeller blade 110
Is a series of side wall slots 18 formed in the starter housing 30 during rotation of the flywheel by the crankshaft.
6 through the external cooling air 1 inside the power head mechanism 20
Including 84. Air 18 entering the power head mechanism 20
4 flows rearward through finned cylinder 100 and muffler 118 to rear lower shroud cavity 74 to cool these portions. Cooling air 1 flowing right through muffler 118
84 cools the exhaust gas by mixing with the exhaust gas discharged from the muffler 118. Mixture of cooling air and exhaust gas 184,186
Is discharged rearward from the muffler guard 160 through the rear end wall opening 158 as shown in FIG. The cooled exhaust gas and the cooled air-fuel mixture are discharged backward away from the trimmer operator.

A crankshaft weight member 188 in a rear portion 122 of the crankcase 106 is fixed to an inner end of the crankshaft portion 172. The weight of the crankshaft mechanism 104 has a crankpin 190 operably connected to the piston 102 by a connector 192.

The clutch mechanism 112 is coaxially mounted on the outer end of the crankshaft 180 and is held by a nut 194 fixed to the screw end 182 of the crankshaft. An annular clutch washer 196 is coaxially mounted on the shaft 180 and is supported on the rear side of the clutch mechanism 112. The inner end of the long flywheel weight member 198 is slidably held by the shaft portion 180, and the side portion 2
It is supported at the center of 00. Weight member 198 is shaft part 180
, And is held in contact with the flywheel surface 200 by a tubular retainer sleeve 203 mounted on the shaft portion 180 and having both ends held by a clutch washer 196 and a weight member 198.

The weight member 198 is located on the right end of the crankshaft when the piston 102 is near the top dead center and the bottom dead center.
2. It has the function of substantially reducing the vibration of the engine resulting in the linear inertia force and reaction force of the control rod 192 and the related connecting parts. The weight member 198 is aligned with the flywheel so that when the piston is near the top dead center and the bottom dead center, the longitudinal axis of the weight member swings parallel to the piston axis, and the reaction force appropriately directed to the crankshaft. , The swing torque (rocking) applied to the right crankshaft is canceled by the linear inertia force and the reaction force. Weight member 198
The outer end of the weight member 198 is received and retained between adjacent pairs of flywheel impeller blades 110 to provide proper alignment of the flywheel with the flywheel 108.

In a conventional manner, the flywheel 108 has a magnet (not shown) embedded in the periphery that is rapidly driven through the ignition module 114 and transmits the electric spark to the spark plug 116 via the wire 144. doing. Snap switch kill switch 201 (Figs. 1 and 2)
Is attached to the top of the fan housing 26 and the wire 14
4 (not shown) to selectively or quickly shut off the engine. As shown in FIG. 3, the downwardly extending spark plug 116 is provided with a front guard and support 202 extending below the main shroud 24.
It is located near the back of. The support portion 202 has a function of supporting the power head mechanism when the power head mechanism is placed on the ground, and a function of preventing the spark plug protruding outward from being damaged.

The starter housing 30 forms part of a manual starter device 204 having a starter pulley 206 rotatably mounted on the starter housing support post 88. Pulley 206 has starter housing post 88
And is operatively connected to an illustrated annular torsion spring member 208 held between the inner pulley flange 210 and the front wall 86 of the starter housing 30. A central cylindrical hub 214 having a series of ratchet drive teeth 216 therearound extends rearward from the outer pulley flange 212.

Starter rope 218 is wrapped around pulley 206 and has grommeted opening 222 in starter housing 30.
And has an outer end 220 secured to a substantially T-shaped starter pull handle. The inner end 226 of the rope 218 extends outwardly through a pulley threaded opening 228 formed in the flange 212 to provide a pulley drive hub 214
Tied or fixed around

In the conventional method, when the handle 224 is pulled upward in FIG. 3, the pulley 206 rotates rapidly due to the extension of the starter rope 218, and the torsion spring 208 is wound up. At the same time, the drive hub teeth 216 engage the spring-loaded starter dog 230 on the flywheel 108 to rotationally drive the flywheel, or crankshaft, and start the engine. When the engine is started, the dog 230 is separated from the starter teeth 216 centrifugally, and the starter mechanism is released from the balance of the engine. When the handle 24 is opened, the wound torsion spring 208 is activated,
The starter rope 218 is wound up on the pulley 206 as shown in FIG.

The clutch housing 32 cooperates with the clutch mechanism 112 to drive and transmit torque to the trimmer cutting head 14 (FIG. 1) via a flexible drive shaft 234 provided within the trimmer shaft 12 within the linear structure 238. Coupling device 232
Form part of Although not according to the features of the present invention, this flexible drive system, U.S. Pat.
Similar to that described in 983.

The drive and coupling device 232 is provided in the rear portion of the clutch housing 32 as shown in FIG. 3, and has a clutch drum 240 having an open rear end and circumscribing the clutch mechanism 11. The front side wall 242 of the clutch drum 240, which has become smaller in the radial direction, is locked so as not to rotate relative to the flange portion 244 of the hollow tubular connecting member 246.
The coupling member 246 extends axially into the support shaft 94 and extends into the inner end 12a of the trimmer shaft 12 in the support shaft 94. The connecting member 246 is rotatably supported in the hollow support shaft portion 94 of the clutch housing 32 by an annular bearing 248. Bearing 24
8 is a support shaft similar to the adjacent annular bearing washer 250
It is formed integrally with the inner end of 94. Formed bearing 248 and washer 250 are coupled to a pair of annular lip flanges 252,254.
, And is held in the inner end of the support portion 94.

The tubular connecting member 246 is provided on the shoulder 24 located on one side of the bearing 248.
4 and a suitable snapping member 256 fixed to the member 246 and located on the opposite side of the bearing 248, is held by the support member 94. The inner end of the flexible drive shaft 234 is
In the front end of 46, it is slidably received in a shaft hole of a corresponding shape, and the shaft 234 and the connecting member 246 are locked so as not to rotate relative to each other.

The inner end 12a of the trimmer shaft 12 is
Keyed or rotated in the cylindrical support 94 of
The relative rotation between the two is prevented. As shown in FIG. 2, the outer end of the clutch housing 32 which removably receives the inner end 12a of the trimmer shaft 12 is provided with an axial slit along the center as indicated by reference numeral 258. . The inner end 12a of the trimmer shaft is detachably held in the outer end of the clutch housing 32 by two clamp screws 260. The clamp screw 260 passes through the upper and lower front portions 262, 264 of the clutch housing 32 on both sides of the slit 258 and attracts two portions around the trimmer shaft end 12a.

The clutch mechanism 112 has a substantially conventional structure,
Spring means 2 circumscribing the shaft and engaging the friction member 268
It has a pair of friction members urged radially inward by 70 as shown in FIG. When the engine 22 reaches a predetermined speed, the friction member 268 moves by centrifugal force outward from the hub 266, engages the inner surface of the clutch drum 240, rotates the drum, and moves between the connecting member 246 and the flexible shaft end 256. The rotational force is transmitted from the engine 22 to the trimmer head 214 via the flexible drive shaft 234 through the lock of FIG. When the engine speed falls below this predetermined level, the clutch spring means 270 overcomes the centrifugal force of the friction member 268, disengages the friction member from the frictional engagement of the clutch drum 240, and moves the flexible drive shaft 234 to the engine 22.
Let go.

Returning to the various features of the uniquely shaped shroud 24, in FIGS. 1, 2 and 5, the filter and yoke plate mechanism 120 associated with the carburettor 46 is formed by the opposite rear of the shroud. Shroud recess 76
Located and protected within. The object thus positioned in recess 76 is well protected from damage by other portions of shroud 24. In addition, these parts are easily and quickly accessible for service and service. For example,
As previously mentioned, the carburetor 46 and the filter and chike mechanism 120 are easily and quickly removed by removing a pair of screws 166, 168 (FIGS. 4 and 8) that can be easily accessed from the rear of the shroud. In addition, the carburettor 46 is fixedly protected in the shroud recess 76, and its idle and high / low speed adjusting screws 272, 274, 276 (FIG. 5) can be removed from the shroud 24 side without having to remove related members, cover plates, etc. It can be easily adjusted with a screwdriver.

The shroud 24 advantageously forms the bottom of an upper mounting tank for supplying gasoline to the carburetor 46 via a flexible fuel tube 170, as shown in FIG. The upper shroud wall 58 has an upright flange portion 280 around the periphery thereof, and the flange portion 280 forms a downward recess 282 located above the shroud 24 with the wall 58. To balance the upper mounted fuel tank 278 and the recess 282, a plastic molded tank cover member 286 having a threaded fuel cap 288 is vibration welded to the upper end of the recessed flange 280 at its open lower end 290. Flexible fuel tube 170 passes upwardly through a suitably sealed opening (not shown) formed in lower tank wall 58 and has a weighted fuel inlet filter element 292 at its upper end.

The unique shape of the main shroud portion 24 of the power head mechanism 20 is, as described above,
It forms a convenient multifunctional "base" to which power head mechanism components having 6, 30, 32 are connected and supported. These overlapping housing structures cooperate well with the main shroud 24 to provide substantially good maintenance for the engine 22 mounted and supported on the shroud in the manner described below.
Provides accessibility for service and parts replacement.

The quick accessibility to the clutch mechanism 112 is simply 4
Remove the two mounting screws 34 (Fig. 2) and move the drive and coupling 23 away from the balance of the power head mechanism to the left.
2 Pull the clutch assembly appropriately positioned by the nut 194
Achieved by exposing 112. The clutch friction member 268 is inspected, repaired, or replaced as needed.
At the same time, the clutch drum 240 is easily replaced. When removing the drive and coupling mechanism 232 from the trimmer shaft, the clamp screw 260 (FIG. 2) is simply loosened and the drive and coupling mechanism 232 is moved to the end 1 of the trimmer shaft.
Simply subtracted to the right from 2a.

When drive and coupling mechanism 232 is removed from starter housing 30, exposed clutch mechanism 112 is exposed.
Holds the starter mechanism 204 on the crankshaft. When checking the starter mechanism 204, the necessary operation is to remove the end nut 194 of the crankshaft, slide the clutch mechanism to the left from the crankshaft, and slide the starter mechanism 204 to the left from the crankshaft as well. It is to make it.

All flywheel 108 and ignition module 1
Access to 14 is possible by simply removing screw 28 (FIG. 2) and removing fan housing 26. After the fan housing 26 has been removed in this manner, the engine is simply removed by removing the four engine mounting bolts 134 (FIG. 4) and the spark plug 116 and pulling the removed engine from the open front end 56 of the shroud 24.
All 22 structures are removed. In a likewise rapid manner, the removal of the screws 166, 168 (FIG. 4) removes the carburetor 46 and the filter yoke plate mechanism 120. Reassembly of power head 20 is accomplished by reversing these removal steps.

6A and 6B.
Has a structure that facilitates the initial or intermediate repair installation of the starter rope 218. Pulley drive hub 214
Starter rope pulley 206 coaxially mounted on
Are accommodated in an arcuate guide structure partially defined by moldings 294 and 296 bent and extended in the axial direction. The moldings 294 and 296 are four molding bosses 2 spaced in the circumferential direction.
Located radially inward of 98, each boss has an axial bore 34a for receiving four mounting screws 34 (FIG. 2).

A substantially V-shaped groove 300 projecting radially outward is formed at the left end of the guide molding 296. The right end of the molded body 296 is used to hold the radially outer end of the torsion spring 208. The thick portion 302 (FIG. 3) of the starter housing 30 is positioned and fixed radially outside the guide molding 296 by small screws 304 and longitudinal pulley holding tabs 306.
6A and 6B, the radially inner end of the tab 306 is located on the radially outer surface of the outer pulley flange 212 to prevent the pulley 206 from being axially displaced from the drive hub 214. doing. A small semicircular notch is formed on the outer periphery of the outer pulley flange 212 for the purpose described below.

With the manual starter device 204 removed from the power head 20 as described above, the starter rope 218 is replaced in the following quick, convenient and secure manner. For purposes of illustration, assume that the starter rope 218 shown in FIG. 6A has worn and needs to be replaced. The worn rope 218 for replacement is first removed from the pulley and discarded.
Next, the torsion spring 208 wound by hand with the pulley 206 is completely wound, and is released by substantially one rotation until the notch 308 of the pulley flange is aligned with the guide V-groove 300 as shown in FIG. 6B. When manually rolling pulley 208 and thereafter, tab 306 serves to hold pulley 206 on hub 214 and spring 208 prevents the rope changer from being injured. When the groove 300 and the notch 308 are aligned as shown in FIG.
8 is inserted from the axial direction in the space between them and locks the pulley against rotation caused by winding up the torsion spring 208. With the pin member 310 inserted in this way, the pulley can be released, and both hands of the operator can be freely set to attach a new starter rope.

When the pulley is temporarily locked in this manner, the pulley slot 228 is circumferentially aligned with the grommeted rope opening 222. The outer end of the new starter rope is fixed to the starter pull handle 224 and the inner end of the rope is passed through the space between the pulley flanges through the grommet opening 222 and out of the opening 228 and driven as shown in FIG. 6A. It is fixed around the hub 214. During the rope attaching operation, it is important that both hands of the operator become free by the locking operation of the pin member 310, and that the wound spring 208 is safely prevented from being opened by the action of the holding tab 306.

As described above, all that is required is to hold a portion of the new rope and the housing 30 near the grommet opening 222 with one hand and remove the pin member with the other hand. The portion of the new rope located outside the housing slides from the finger, and the torsion spring 208 opens to automatically wind the new rope 218 onto the pulley 206 and moves against the housing 30 as shown in FIG. Pull the handle 224. It can be seen that extremely safe maintenance can be achieved at low cost by the starter device 204. That is, what is necessary for holding the rope is the groove 300, the notch 308, the screw 304, and the holding tab 306.

Other features of the trimmer 10 according to the present invention are shown in FIGS.
4 shows the structure and operation of the filter and the yoke plate mechanism 120 shown in FIG. The filter housing 164 has a substantially rectangular shape, and the side wall 314 has a series of air intakes 316.
The flange 318 projects forward to form an open front end, and the rear inner peripheral end 320 is formed near the flange 318 and inside. Support pin 322 forward from rear wall 312
Around the series of support pins 322, a foamable air filter material 324 in the filter housing 164 is bent. The housing 164 has a notch 320 extending rearward from the front right end 320.

The yoke plate 162 is provided in close contact with the flange 318 and is pressed against the end 320 by a screw 168. Plate 16
The second end 328 is received in front of the notch 326. The lower lever 330 is plate-shaped and has a mounting screw 166 at its center.
One of which is pivotally attached to the rear surface of the yoke plate 162. The inner end 332 of the lever 330 covers the whole or a part of the central circular chiyoke opening 334 formed in the plate 162, and performs chiyoke adjustment of the engine 22.

The lever 330 is connected to the end 328 of the plate 162.
And has an outer end 336 extending outwardly therefrom and having a forwardly bent end 338 at the outer end. End 338 is easily manipulated by a finger to selectively pivot lever 330. The pivoting of the lever 330 is regulated by stop pins 340, 342 extending behind the plate 162, and a suitable stop means 34 is provided.
4,346,348 are formed on the rear surface of the plate 162. These stop means have a shape that is compatible with the protrusion 350 on the outer chain yoke lever end 336 to hold the lever in one of three yoke positions.

The filter housing notch 326 is formed by the yoke plate fixed to the filter housing 164 as described above.
The front edge portion 324a of the foam filter member 324 near the inner side is pressed against the inner side surface 162a of the plate 162, and is also pressed around the outer protruding end portion 336 of the chi-yoke lever 330 (FIG. 9). A movable dust seal 352 is held around the clever portion 336. As shown in FIG.
When the lever portion 336 moves downward from its solid line position to its dotted line position, the seal 352 moves together with the lever portion, and the portion of the filter member side surface 324a pressed by the lever portion 336 to the solid line position is the inner surface 162a of the plate 162. Engage. The movement between the foam filter member 324 and the lever 330 results in a reduction in the amount of unfiltered air reaching the filter 46.

Another feature of the present invention is the mechanism and operation of the shield strap mechanism 52, which will be described with reference to FIGS. Even though the inherent flexibility of the shoulder strap 54 significantly reduces the axial vibration transmitted to the trimmer user, a significant amount of axial vibration can be achieved in conventional composite clamp members that connect the outer end of the strap to the shaft. Is a strap
Informed to the user via 54. A significant amount of undesired and occasionally fatigued axial vibrations transmitted through the strap 54 are restrained by the resilient coupling mechanism 52. The elastic connecting mechanism 52 has a substantially U-shaped plastic forming clamp portion 354, and its arms 356 and 358 are provided on the trimmer shaft 12.
Extending below the clamp screw and locking nut device 360,
It is attracted to each other by 362 and attracts the base 364 of the clamp member 354 to the shaft 12. The protruding base 366 of the plastic forming connecting member 368 is fixed to a closed upper portion of the base 364 by a screw 370 extending in a radial direction. The screw 370 extends upward through an alignment hole formed in the bases 364 and 366, and is housed in the radially inner concave portion 374 in the base 364.
It has 372 and is screwed into the locknut 376. Lock nut 376 is located along the longitudinal middle of screw 370 and is housed in a recess 378 formed in base 366 as shown. Further, the clamp portion 354 and the connecting member 368 may be integrally formed as necessary.

The connecting member 368 is a hollow substantially barrel-shaped vibration separating member 3.
84 has an annular upper end 380 having a radially inner portion held by an annular outer channel 382 formed on the side surface. The separating member 384 is made of a suitable elastic member and has a resistance taper portion 386, 388. The opposite end is received by a substantially dish-shaped separating supporting member 390, 392 near the inside of the lower end 394, 396 of the U-shaped metal snap connecting member 398. Have been.

The member 398 is fixed to the elastic separating member 384 by a connecting bolt 400, and the connecting bolt 400 is connected to the connecting member tanks 394, 39.
6, Dish-shaped members 390,392, tapered end 386,388 of separating member 384
And the inside of the separating member. The outer end of the bolt 400 is screwed into the holding nut 402. Other fixing tools such as rivets can be used instead of the bolts 400.

The tubular metal spacer 404 is located inside the separating member 384, coaxially engages with the longitudinal center of the bolt 400,
The separation member 384 is supported at its opposite end against the inner surface of the outer end 386, 388. The illustrated looped outer end of the shoulder strap 54 passes through the rectangular slide loop end 406 of the small clip member 408 and the clip member 408 can be directly attached to the snap connection member 398 or as shown in the member 398.
Is attached to the split ring adapter 410 connected to.

Due to the hollow shape of the separation member 384 which is flexible in the radial direction and the axial direction, the snap connection member 398 is connected to the base 36 of the connection member 368.
It can be seen that it is completely separated from 6. Therefore, the shoulder strap 54 is connected to the clamp member 354 via the connecting structure.
Many of the shaft vibrations transmitted to are absorbed and reduced by the separation member 384.

A modification 20a of the power head mechanism 20 of the present invention is shown in FIG. For comparison, members similar to the powerhead mechanism 20 are shown with a suffix (a). The engine and clutch elements in the shroud and housing structures 24a, 26a, 30a, and 32a are the same as the power head mechanism 20,
The engine has a filter housing yoke plate mechanism 120a mounted externally and a carburetor 46a mounted on the shroud support 68a.

However, in the power head mechanism 20a, the protection recess 76a at the rear end of the main shroud 24a is not completely defined by the shroud itself. Instead, shroud 24a has an upper rear wall 412 that slopes forward and upward. The rear wall 412 is almost flat front upper wall
414 and the inner wall of the intermediate wall 70a.
Is formed to the immediate vicinity of the flat upper wall portion 416 of the fan housing 26a. The further modified shroud 24a does not define the gas tank portion of the power head mechanism. Instead, separate plastic forming gas tanks 418 are provided on the upper walls 414, 416 of the shroud and fan housings. The tank 418 has a rear portion 420 extending downward from the rear along the shroud wall 412. The tank rear part 420 has a bottom wall part 422 inclined rearward and upward, and forms a protective recess 76a with the shroud walls 68a, 70a. The tank 418 is connected to the front side 42 fixed to the rear shoulder 426 of the fan housing 26a by a suitable connecting bracket structure 428.
Has four. The tank rear 420 can be mounted on the sloped wall 412 of the shroud by suitable connecting lip means (not shown) if necessary.
Can also be fixed.

Another modification 20b of the power head mechanism 20 is shown in FIG. The power head mechanism 20b is a direct drive (i.e., no clutch) type of the power head 20, and has many changes. The shroud 24b is substantially the same as the shroud 24a of FIG. 12, but instead of a separate, stacked and fixed fan, starter and clutch housing, the shroud 24b is integrally formed with the coupling, starter and fan from front to back. Secures an integral housing structure 430 having portions 432, 434, and 436. The integrated housing structure 430 is similar in appearance to the stacked housings 26a, 30a, 32a of FIG. 12, but the coupling portion 432 is short and the power head mechanism 20b has no clutch.

In FIG. 14, the flywheel 108b is provided in the fan portion 436, and the torsion spring 208b and the starter pulley 206b are provided in the starter portion 434 of the integral housing structure 430. In the no-clutch type of power head mechanism, the outer end 180b of the crankshaft is considerably shorter and projects outward at a small distance from the center flywheel surface. The flywheel overlap 180b is provided on the flywheel surface 200b. The crankshaft end 180b is locked in the right end of the hollow tubular coupling member 438, and the coupling member 438 extends coaxially with the inner end of the support shaft portion 94b of the coupling portion 432. The left end of the coupling member 438 receives the corner end 256 of the flexible drive shaft 234 so as not to rotate, and as described with respect to the clutch housing 32 of the power head device 20, the coupling portion 43
Within 2 is a trimmer axis 12. In this embodiment, the flywheel weight is held on the flywheel surface 204 by the right end of the coupling member 438.

The starter pulley 206b is attached to the small-diameter inner end 440 of the support shaft 94b (which replaces the support post 88 in FIG. 3), and is held by a holding means such as a washer 444 fixed to the thick wall portion 446 by a small screw 448. It is in contact with the shoulder part 442 of 94b along the front end. The torsion spring 208b is held on one side by the pulley flange 210b and on the other side by the shoulder 442 and the housing shoulder 450. Access to the components of the starter device, flywheel and engine, as shown in FIG. 14, is achieved by removing the integral housing structure 430 from the main shroud 24b.
Replacement of the starter rope is accomplished safely and easily in the manner described for FIGS. 6A and 6B.

In another modification of the power head mechanism 20b, similarly to the power head device 20a, the shroud 24b does not integrally form the gas tank portion of the power head mechanism 20b.
Instead, a separately molded plastic gas tank 452 is secured to the rear end of the L-shaped operating handle 454, and the handle 454 is spaced upwardly from the shroud and housing walls 414b, 416b. Tank 452 is shroud wall 412
b and a filter and a yoke plate device 120b
Located on the carburetor 46b and partially defining a protective recess 76B in which the member is received. Handle 454
A downwardly curved front end 456 is secured at a location 458 to a support web 460 integrally formed with the housing structure 430 and extends forward and upwardly therefrom to lie at the upper ends of the starter and fan sections 434,436. The handle 454 has a throttle trigger 460 pivotally mounted near the handle front end 456. The trigger 460 is connected to the tab slot through suitable cable means in a manner not shown. When such a power head mechanism is used, the handle 454 serves as a control handle for a rear worker, and the cylindrical hand grip 36 and the throttle control structure shown in FIG. 1 can be omitted. This power head mechanism is applied to the trimmer 10.

Comparing the power head mechanisms 20, 20a, 20b described above, it can be seen that each is configured as a unique modular, which facilitates cost and manufacturing and can be disassembled for good maintenance inspection and repair. The unique modular construction allows for improved access to the internal components of the powerhead, allowing tool purchasers to easily perform maintenance, repairs and tank changes.

Referring again to FIGS. 3 and 4, the power head device 20 will be described.
The easily splittable module or part (same perspective as the device 20a in FIG. 12) comprises a shroud 34, an engine module of the engine 22 fixed to the shroud, a fan housing module having a fan housing 26, and a starter device 204. And a coupling module constituted by a drive module and a coupling mechanism 232.

In the direct drive type power head mechanism shown in FIG. 13, there are two divided modules. That is, a starter and a cup defined by a front housing structure 430 integral with an engine module constituted by a slightly modified shroud 24b and an engine fixed thereto and a starter and a coupling structure detachably supported therein. There is a ring module.
Comparing the power head mechanisms 20 and 20b, the fan housing, starter and coupling module of the device 20 are characterized as integral housings, starter and coupling module sub-modules of the device 20b and correspond to the presence of the clutch mechanism 112.

As mentioned above, in the embodiment of the present invention, a portable rotary automatic tool is provided to provide various advantages, i.e., structure, operation,
It has features in maintenance, service proximity costs, convenience and comfort. It goes without saying that the principle of the present invention is not limited to the illustrated automatic tool of the characteristics, but many modifications are possible.

[Brief description of the drawings]

FIG. 1 is a perspective view of a gasoline engine powered automatic flexible line trimmer having structure, operation, maintenance, service proximity, low cost, and other improvements embodying the principles of the present invention, and FIG. FIG. 3 is an enlarged perspective view of the power head, FIG. 3 is a schematic cross-sectional side view of the power head section taken along line 3-3 in FIG. 2, and FIG. FIG. 5 is a schematic exploded view of the power head portion with parts omitted, FIG. 5 is a cutaway view of the rear portion of the power head taken along line 5-5 in FIG.
6A and 6B show a rear elevational view of the starter housing portion of the power head section taken along line 6-6 in FIG. 4, showing features of the structure and operation of the recoil starter mechanism, and FIG. 7 is a view of the power head section. FIG. 8 is an exploded perspective view of the device of FIG. 7, FIG. 9 is an enlarged cutaway view taken along line 9-9 of FIG. 7, and FIG. An enlarged perspective view of a vibration separating shoulder strap connecting portion fixed to a portion of a trimmer shaft shown by a broken line,
FIG. 11 is a cross-sectional view of the connecting member taken along line 11-11 of FIG. 10,
FIG. 12 is a side view of a modified example of the power head section, FIG. 13 is a side view of another modified example of the power head section, and FIG.
FIG. 2 is an enlarged partial cross-sectional view of a front end portion of the power head shown in FIG. 10 ... Flexible line trimmer, 12 ... Longitudinal hollow shaft, 14 ... Rotation drive cutting head mechanism, 16 ... Trimming line member, 18 ... Protective shield member, 20 ... Power head mechanism or power head mechanism, 22 ... ... internal combustion engine (engine), 24 ... main shroud, 26 ... fan housing, 28 ... mounting screw, 30 ... starter housing, 32 ... clutch housing, 34 ... mounting screw, 36
…… Hand grip, 38 …… Throttle lever housing, 40 …… Throttle lever, 42 …… Cable, 44 ……
Arm part, 46 …… Carburetor, 50 …… Worker handle, 52 …… Shoulder strap connector, 54 …… Strap, 56 …… Opening front end, 58 …… Shroud upper wall, 60…
… Bottom wall, 62,64… side wall, 68 …… upper back wall, 70 …… bottom side, 72 …… bottom rear end opening, 74 …… cavity, 76 …… recess, 78 …… tab, 80… ... Open front end, 82,84 ... Open rear end, 86 ... Front wall, 88 ... Support member, 90 ... Open rear end, 92
…… Open front end, 94 …… Support shaft part, 100 …… Cylinder with fin, 102 …… Piston, 104 …… Crank shaft mechanism, 106 …… Crank case, 108 …… Fly wheel,
110… impeller blade, 112… clutch mechanism, 114
... Ignition mold, 116 ... Spark plug, 118 ... Muffler, 120 ... Air filter housing and chi-yoke plate mechanism, 122 ... Hollow rear, 124
…… Open rear end, 126 …… Open lower side, 128 …… Bearing support part, 132 …… Boss part, 134 …… Mounting bolt, 136 …… Boss opening, 138 …… Crankcase reed valve, 140 …… Seal Gasket, 142 ... opening, 144 ... wire, 146 ...
... Block, 148 ... Mounting screw, 150 ... Outlet opening, 15
2 ... Inlet end, 154 ... Muffler liner, 156 ... Outlet, 158 ... Back wall hole, 160 ... Muffler guard, 162 ...
Cylinder plate, 164 …… Air filter housing, 166 …… Mounting screw, 168 …… Mounting screw, 170 …… Flexible fuel tube, 172 …… Coaxial portion, 174 …… Inner crank bearing, 176 …… Outer crank bearing, 180 ……
Shaft, 182: Outer end, 184: Cooling air, 186: Rear wall slot, 188: Weight member, 190: Crank pin, 192: Knob, 194: Nut, 196: Washer, 198 ... weight member, 200 ... side view, 203 ...
Retainer sleeve, 202 Support section, 204 Manual starter device, 206 Pulley, 208 Torsion spring, 210 Inner flange, 212 Outer flange, 214
…… hub, 216 …… ratchet drive shaft, 218 …… starter rope, 220 …… outer end, 222 …… grommet opening, 22
4 Handle, 226 Inner end, 228 Pulley opening, 230 Starter dog, 232 Coupling device, 234 Flexible drive shaft, 238 Linear structure, 24
0: Clutch drum, 242: Front wall, 244: Flange, 246: Connection member, 248: Bearing, 250: Bearing washer, 252, 254: Tubular lip flange, 256:
… Snapping member, 260 …… Clamp screw, 262,264
...... front part, 266 ... hub, 268 ... friction member, 270 ... clutch spring means, 272, 274, 276 ... adjustment screw, 278 ... fuel tank, 280 ... upright flange part, 282 ... ... concave part, 286
... tank cover, 288 ... fuel cap, 290 ... bottom end, 292 ... filter element, 294,296 ... molded body, 298 ... molded boss, 300 ... V-groove, 302 ... thick part, 3
04 Machine screw, 306 Tab, 308 Notch, 314 Side wall, 316 Air intake, 318 Flange, 320
... inner end, 322 ... support pin, 324 ... air filter material,
326 …… Notch, 328 …… End, 330 …… Yoke lever, 3
32 …… Inner end part, 334 …… Chiyoke opening, 336 …… Outer end part,
338 …… End, 340,342 …… Stopper pin, 344,346,34
8 ... Stopping means, 350 ... Protrusion, 352 ... Dust seal, 3
60,362 …… Lock nut, 364 …… Base, 366 …… Base,
374 recess, 378 recess, 380 end, 382 channel, 384 separation member, 386, 388 taper, 39
4,396 ... Bottom, 390,392 ... Support member, 400 ... Connecting bolt, 402 ... Nut, 404 ... Spacer, 408 ... Clip, 410 ... Adapter, 412 ... Wall, 414 ... Wall, 416 …… Top wall, 418 …… Tank, 420 …… Rear part, 424…
… Side part, 430… housing structure, 434 …… starter part, 438 …… coupling part, 448 …… screw, 450 …… shoulder, 452… tank, 454 …… handle, 456 ……
End, 460 ... web.

Claims (2)

(57) [Claims] 1. A working device that can be driven to perform a predetermined working function, a power transmission device that receives torque from a power source thereof, transmits the rotating force to the working device, and drives the working device; An automatic tool driven by an internal combustion engine having a head mechanism, wherein the power head mechanism has a shroud member, the shroud member has an opening front end, and an engine support wall formed rearward from the opening front end. A fuel / air mixture passage extending through the support wall from an outer surface to an inner surface of the shroud member; a reed valve secured to the inner surface of the support wall above the fuel / air mixture passage; A chamber extending rearward of the support wall, the chamber communicating with the inside of the shroud member and having a rear end release portion, and the power head mechanism further generates a rotational force. Internal combustion engine Wherein the internal combustion engine has a crankcase partially surrounded by a shroud member, and an open rear end of the crankcase is fixed to the support wall portion over the reed valve; The rear surrounding wall of the crankcase is formed by the, the internal combustion engine is supported by the engine support wall portion via the crankcase,
The internal combustion engine further includes a cylinder connected to the side of the crankcase in the shroud member, a muffler fixed to the cylinder and located inside the chamber, and a muffler fixed outside the support wall and A carburetor operatively positioned over a fuel / air mixture passage, the powerhead mechanism further comprising: a housing member removably connectable to the shroud member at the open front end; A coupling device rotatably connecting the internal combustion engine to the power transmission device; and a coupling device supported inside a part of the housing member to start the internal combustion engine and connect the starter device to the shroud. A manual starter device that can be removed from the member. 2. A working device that can be driven to perform a predetermined working function, a power transmission device that receives torque from a power source thereof, transmits the rotating force to the working device, and drives the working device. An automatic tool driven by an internal combustion engine having a modular power transmission for transmitting power to the power transmission, the modular power transmission comprising an engine module, a shroud member having an open front end, and a wall of the shroud member. An engine supported and fixed by a part, the engine has a crankcase and a cylinder part arranged in the shroud member, and the crankcase and the cylinder part are detachable from the opening front end, A flywheel having a front longitudinal portion protruding forward from the opening front end of the shroud member; An engine module coaxially held and locked to a front longitudinal portion of the crankshaft; a removably mounted front end of the opening of the shroud member and surrounding the flywheel and the front longitudinal portion of the crankshaft. A housing portion; a coupling device located in the housing portion and rotatably connecting the internal combustion engine to the power transmission device; and a starter device supported by the housing portion and starting the internal combustion engine, wherein the starter device is the shroud. A manual starter device that is removable from the member.